Satake H, Kawashima T, Suzuki M, Matsunami K
Department of Neurophysiology, Gifu University School of Medicine, Japan.
Neurosci Res. 1993 Feb;16(2):105-15. doi: 10.1016/0168-0102(93)90077-4.
Neuronal responses to electrical stimulation at the horizontal ampulla (HA), vestibular nerve (at the windows) and corpus callosum (CC) were investigated in neurons in the anterior suprasylvian gyrus of the cat. The field potentials to HA stimulation had short latency: 2.9 +/- 0.3 (mean +/- SD) ms from the stimulus to the onset and 5.6 +/- 1.9 ms to the peak. The focus of the evoked potentials was located in the anterior suprasylvian (ASS) gyrus or near the ASS sulcus. HA stimulation activated 6 neurons out of 674 examined, with the mean latency of 4.3 +/- 1.1 ms. Of these 6, four neurons also responded to window stimulation. Fifty-six neurons responded to window stimulation with the mean latency of 6.1 +/- 2.4 ms. The mean latency for CC stimulation was 1.9 +/- 0.9 ms (n = 76). Four neurons responded to CC stimulation antidromically (mean = 0.9 +/- 0.3 ms) and one of them also responded orthodromically. The convergence of CC inputs in relation to HA or window stimulation was examined. One (17%) of the 6 HA-activated cells responded to CC stimulation, compared with 8 (14%) of the 56 neurons activated by window stimulation. The other 612 neurons did not respond to either HA or window stimulation, and 80 (13%) of the 612 responded to CC stimulation. Therefore, it is concluded that neurons in the ASS gyrus received callosal input equally irrespective of the presence or absence of responses to ampulla or window stimulation. WGA-HRP was injected in the ASS gyrus to identify the passing callosal fibers in the CC. Fibers from the ASS area passed at the rostral third of the CC. The present results indicate that the ASS area received vestibular projection with short latency, but responses of this projection did not seem to be very strong, at least from the present unit study, to HA stimulation. Discussion was made on the poor neuronal responses to electrical HA stimulation in comparison with previous studies. Also consideration was made on neuronal activity to CC stimulation.
在猫的前上薛氏回的神经元中，研究了水平壶腹（HA）、前庭神经（在视窗处）和胼胝体（CC）电刺激引发的神经元反应。HA刺激产生的场电位潜伏期较短：从刺激开始到起始为2.9±0.3（平均值±标准差）毫秒，到峰值为5.6±1.9毫秒。诱发电位的焦点位于前上薛氏（ASS）回或ASS沟附近。在674个被检查的神经元中，HA刺激激活了6个神经元，平均潜伏期为4.3±1.1毫秒。在这6个神经元中，有4个也对视窗刺激有反应。56个神经元对视窗刺激有反应，平均潜伏期为6.1±2.4毫秒。CC刺激的平均潜伏期为1.9±0.9毫秒（n = 76）。4个神经元对CC刺激产生逆向反应（平均值 = 0.9±0.3毫秒），其中1个也产生顺向反应。研究了与HA或视窗刺激相关的CC输入的汇聚情况。在6个被HA激活的细胞中，有1个（17%）对CC刺激有反应，而在56个被视窗刺激激活的神经元中，有8个（14%）对CC刺激有反应。另外612个神经元对HA或视窗刺激均无反应，在这612个神经元中有80个（13%）对CC刺激有反应。因此，可以得出结论，无论对壶腹或视窗刺激有无反应，ASS回中的神经元都同样接受胼胝体输入。将WGA-HRP注入ASS回以识别CC中通过的胼胝体纤维。来自ASS区域的纤维在CC的前三分之一处通过。目前的结果表明，ASS区域接受前庭投射的潜伏期较短，但至少从目前的单位研究来看，这种投射对HA刺激的反应似乎不是很强。文中讨论了与先前研究相比，神经元对HA电刺激反应较弱的情况。还对神经元对CC刺激的活动进行了考量。
